Identify $X$ and $Y$ in the given diagram of secondary growth in a dicot stem.

The waxy substance associated with the cell walls of cork cells that makes them impervious to water is:

Identify the correct statements:
$A$. Lenticels are the lens-shaped openings permitting the exchange of gases.
$B$. Bark formed early in the season is called hard bark.
$C$. Bark is a technical term that refers to all tissues exterior to vascular cambium.
$D$. Bark refers to periderm and secondary phloem.
$E$. Phellogen is single-layered in thickness.
Choose the correct answer from the options given below:

Complementary cells are formed by the activity of ..........

Cork is obtained from:

$A$ timber merchant told a customer that the log of wood he is purchasing belongs to a $20$-year-old tree. He did so by